Browse Prior Art Database

Lightning Surge Suppressor

IP.com Disclosure Number: IPCOM000042430D
Original Publication Date: 1984-May-01
Included in the Prior Art Database: 2005-Feb-03
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Abramson, P: AUTHOR [+4]

Abstract

This article describes a plurality of devices for protecting electrical equipment from high voltage surges, such as those caused by lightning, etc. Fig. 1 shows one of the circuit configurations. The circuit is comprised of silicon diodes D1, D2, D3 and D4. The silicon diodes are connected to bidirectional zener diodes Z1 and Z2, respectively. The zener diodes are connected to a ground potential. In this circuit the silicon diodes (D1, D2, D3 and D4) permit a positive or negative surge voltage to reach the zener diodes Z1 and Z2. Because the silicon diodes have much lower capacitance than the zener diodes, and this capacitance is in series with the capacitance of the zener diodes, the resulting capacitance is very small and the data signal is attenuated very little. The circuit of Fig.

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Lightning Surge Suppressor

This article describes a plurality of devices for protecting electrical equipment from high voltage surges, such as those caused by lightning, etc. Fig. 1 shows one of the circuit configurations. The circuit is comprised of silicon diodes D1, D2, D3 and D4. The silicon diodes are connected to bidirectional zener diodes Z1 and Z2, respectively. The zener diodes are connected to a ground potential. In this circuit the silicon diodes (D1, D2, D3 and D4) permit a positive or negative surge voltage to reach the zener diodes Z1 and Z2. Because the silicon diodes have much lower capacitance than the zener diodes, and this capacitance is in series with the capacitance of the zener diodes, the resulting capacitance is very small and the data signal is attenuated very little. The circuit of Fig. 1 provides a very good protective circuit for data signals whose amplitude is a maximum of 1.6 volts peak-to-peak. If the signal voltage is greater than this, the silicon diodes become forward biased due to the signal. The capacitance of the zener diode then appears across the line and attenuates the data signal. This problem may be solved by adding additional silicon diodes, as shown in Fig. 2. Each additional pair of diodes adds 1.6 volts to the allowable amplitude of the data signal. Thus, by the addition of a sufficient number of silicon diodes, a signal of any voltage level may be accommodated. The circuit of Fig. 3 is a more effective circuit. A bri...